As Arches owner Phil lies unconscious, Jack is convinced he has killed him. In a panic, he calls his brother Max for advice - but when he fails to answer he decides the only thing he can do is flee the scene.

Desperate to stay out of jail, he races home to pack a bag but is interrupted by Dot, who marches him across for family drinks in the Queen Vic.

Jack reveals all to Max, who tries to persuade him to go and see if Phil is OK. Unable to deal with what he might have done, Jack decides to drown his sorrows as Phil's life hangs in the balance.

An EastEnders insider said: "Phil has spent months tormenting him and Jack finally loses it. He knows all about Phil and Sharon's history but it's his meddling in her life that really gets to him.

"Jack storms over to the Arches to confront him once and for all. He starts by asking Phil to stop messing with Sharon's role at R&R but when he refuses to back down, he punches him.

"All the anger that has built up inside him just comes out.

"But it's what he does next that will leave viewers shocked. Fleeing the scene like he does means even more trouble for Phil. With only Jack knowing where he is it's going to take some doing for someone to find him."